The present invention relates to apparatus and methods to assist in the diagnosis of premature ejaculation, particularly but not exclusively for standardising such diagnosis.
In this era of heightened awareness of male and female sexuality, premature ejaculation has been recognised as a very common male sexual health problem, affecting as much as 20-30% of men. Paradoxically, however, it is the disorder for which men are least likely to seek help.
There is no consensus regarding the criteria used to define premature ejaculation. The most recent set of criteria appear in the 4th edition of the Diagnostic and Statistical Manual of the American Psychiatric Association. Implicit in the definition is that the disturbance causes marked distress or inter-personal difficulty parameters that can only be assessed qualitatively. No quantifiable endpoints have been agreed upon.
Little is known about the underlying pathophysiology of premature ejaculation as the disorder has been under-researched. There are emerging data to suggest that men with premature ejaculation have hypersensitivity and hyper-excitability of the glans penis and the dorsal nerve; thus there may be both an organic and psychogenic basis for clinical premature ejaculation.
Individual, conjoint and group psychotherapy approaches combined with behavioural strategies such as xe2x80x9cstop-startxe2x80x9d or xe2x80x9csqueezexe2x80x9d techniques have been used in the treatment of premature ejaculation. However long term success is limited. Several devices are also available (see eg U.S. Pat. Nos. 5,468,212 and 5,535,758).
Increasingly, therapeutic agents have been tried in the management of premature ejaculation (see eg U.S. Pat. Nos. 5,587,167, 5,707,999 and 5,863,927). However, in the absence of a detailed understanding of the aetiology of the disorder, the rationale for the selection of the agents evaluated is often unclear. Not surprisingly, success with oral agents has been limited.
It is an object of the present invention to provide apparatus and methods for providing reproducible quantification of premature ejaculation in men.
According to one aspect of the present invention, there is provided an apparatus to provide a vibratory stimulus to the penis of a male human comprising a cuff able to fit around the penis, which cuff includes one or more vibratory means operable at a pre-determined or variable frequency.
The apparatus of the present invention is able to induce ejaculation in men by the vibratory stimulus applied via a penile cuff. Latency to ejaculation (which is the time period between the start of the stimulus and the ejaculation) can be determined at either a constant vibratory frequency, or at a threshold frequency. The values can be compared to mean values for these parameters obtained historically from normal men, ie those defined as not experiencing clinically significant premature ejaculation. Repeated use of the apparatus and repeated measurements can be made to ensure reproducibility. Desirably the apparatus includes a timing device, preferably an automatic timing device, so that the time to ejaculation is measured.
Advantageously the apparatus further includes control means for controlling the operation of said vibratory means, this control means may be adapted to control the intensity of vibration of said vibratory means. Also, this control means is preferably adapted to control the operation of said vibratory means such that the vibratory means is repeatedly switched alternately on for a first predetermined time period and off for a second predetermined time period.
It is further preferred that the apparatus further includes sensor means adapted to be fitted to the penis. Desirably this sensor means is adapted to detect ejaculation and can be a pulse sensor.
It is further preferred that the apparatus includes means for calculating an event duration comprising the time period between the commencement of stimulation and ejaculation.
It is further preferred that the apparatus further includes data storage means adapted to record at least one of data generated by said sensor means, parameters relating to the operation of said vibratory means and an event duration.
It is further preferred that the apparatus further includes visual display means for displaying at least one of parameters relating to the operation of the apparatus, data and at least one elapsed time period.
It is further preferred that the apparatus further includes interface means whereby the apparatus may communicate with a separate data processing system.
According to a second aspect of the present invention, there is provided a method of measuring premature ejaculation in a male human, said method comprising the steps of:
a) positioning a vibratable cuff to the penis of the human;
b) providing a vibratory stimulus having either a pre-determined constant frequency or a variable frequency to induce ejaculation;
c) measuring the latency time period to ejaculation at said vibratory stimulus and/or the threshold frequency required to induce ejaculation; and
d) comparing said latency measurement and/or said threshold frequency to known standard measurements.
Advantageously the apparatus according to the invention above described is used to carry out said method.
Such a method can be used to diagnose premature ejaculation. In particular a shorter latency time period and/or lower threshold frequency when compared to standard measurement would be an indication of premature ejaculation condition.
According to a third aspect of the present invention, there is provided a method of evaluating a novel potential therapeutic agent for the treatment of premature ejaculation in a male patient wherein an initial assessment of premature ejaculation can be made as a baseline measurement, and then novel potential therapeutic agents administered to the patients. Thus, the method of the invention comprises the steps of
A) providing a first measurement of the latency time period to ejaculation and/or the threshold frequency required to induce ejaculation in the patient by:
(i) positioning a vibratable cuff to the penis of said patient;
(ii) providing a vibratory stimulus having either a pre-determined constant frequency or the threshold frequency required to induce ejaculation; and
(iii) measuring the latency time period to ejaculation at either said constant vibratory or at said threshold frequency required to induce ejaculation;
B) administering said agent to said patient;
C) at a pre-determined time, providing second measurement of the latency time period to ejaculation and/or of the threshold frequency required to induce ejaculation as described in the steps (i) to (iii) below; and
D) comparing said first and second measurements to determine the efficiency of said agent.
Step C) below may be repeated at different period of time to obtain several measurements. Measurements are advantageously repeated at times relevant to the pharmacokinetic profile of the drug, eg within the period 30 minutes to 24 hours after a single oral dose of the agent under evaluation.
Advantageously the efficiency of said agent is shown by an increase of either the latency time period or the frequency of vibratory stimulus to induce ejaculation of the second measurement when compared to the first measurement. Thus, an agent with clinical potential should either increase ejaculation latency, or the frequency of vibratory stimulus to induce ejaculation, when compared to the baseline measurement, by a defined amount. This could generally be by a minimum of 50%. Efficacy could be measured by the use of placebo agents.
In case also, the method is advantageously carried out using the apparatus of the invention described above.
According to a fourth aspect of the present invention, there is provided a method of evaluating substances for treating premature ejaculation wherein a vibratory frequency and/or period of vibration of a vibratory penile cuff around the penis of a patient is measured at a pre-determined time after administration of a substance, and which frequency and/or period for ejaculation are compared with known standard measurements.